Scientist eyes an end to pox

Dr. Rachel Roper is working on vaccines for SARS, monkeypox and other diseases. Photo by Cliff Hollis

GREENVILLE, N.C.
(Nov. 24, 2008)
—
Dr. Rachel Roper, a microbiologist at the Brody School of Medicine at East Carolina University, is studying ways to stop the spread of monkeypox.

Last year Roper, an assistant professor of microbiology and immunology, was among the first group of North Carolina scientists to receive a North Carolina Biotechnology Center Biotechnology Research Grant – in her case, $72,497.

By removing a specific gene that affects immunity, she is drawing attention for her approach that holds promise not only for improving the safety and effectiveness of poxvirus vaccines, but also for killing other viruses such as coronaviruses, which include the human severe acute respiratory syndrome virus.

"Ironically, it's the success of the global smallpox eradication program that opened the door to today's spread of monkeypox," Roper said.

Smallpox is the first disease to be eradicated worldwide, thanks to nearly 200 years of persistent vaccine use. The World Health Organization declared it defeated and stopped its vaccination program in 1980, three years after the last case had been registered in Somalia.

Even though the smallpox vaccination program was hugely successful in wiping out that specific scourge, smallpox is identified by the U.S. government as a primary bioterrorism/biowarfare threat. Also, the halting of the vaccine program has left humans without the "side effect" of increased immunity to the monkeypox virus – a "cousin" of smallpox – for almost 30 years. Now, monkeypox is spreading. In Africa, it’s causing fatality rates frighteningly similar to those once associated with smallpox. The first outbreak of monkeypox hit the United States five years ago in people who played with infected pet prairie dogs.

"The emergence of SARS represents an even more significant viral evolutionary event," Roper said. "It may well be the biggest infectious disease event since HIV."

Before SARS, coronaviruses had received little research attention and caused no significant human disease. But Roper was one of the scientists who sequenced and analyzed the SARS genome and, in 2003, published in Science that this virus belongs to a new, previously unrecognized group of coronaviruses. Roper is the former program director for the British Columbia SARS Accelerated Vaccine Initiative and is senior author on a just-published paper on SARS vaccines.

Using the mega-number-crunching computer technologies of bioinformatics, Roper and her colleagues have been looking for clues as to why some of these viruses are meaner than others. And they're turning up some interesting ones.

Roper's biggest hope is in a vaccinia virus she weakened by removing a gene that surfaced above thousands of others as an ideal target. Called A35R, the gene interested Roper because it seems to inhibit immune responses in mammals. With the help of the Biotechnology Center funding, she's pursuing her hypothesis that removing the A35R gene from poxvirus vaccines will make vaccines safer and more effective against such threats as monkeypox.

And, if bioterrorists somehow find a way to release smallpox, a safe, powerful, wide-ranging vaccine could just help save the world.

Roper's research is featured in a new campaign by the N.C. Biotechnology Center, which can be seen on its Web site, http://www.ncbiotech.org.

This article is an edited version of one written by Jim Shamp, N.C. Biotechnology Center news and publications editor.